The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem and the understanding of the causes of a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section may merely represent different approaches, which in and of themselves may also be inventions.
Medical diagnostic and therapeutic procedures often involve delivering fluids to patients. For example, procedures affecting subcutaneous or internal tissues often utilize catheters to access these tissues. There are many other medical procedures involving delivery of fluids to patients including delivery of medications, nutrients, anesthetic agents, and diagnostic agents. Examples of procedures utilizing catheters include delivery of medicines to tissue sites, measurement of tissue electrical and mechanical properties, imaging of tissues, and ablation of tissues. These procedures may use catheters which require the delivery of fluids to these tissues or the circulation of fluids within the catheter.